Nitrogen generator and uses thereof

ABSTRACT

A system and method to supply nitrogen gas is provided. Ambient air is compressed and stored in a storage receiver and then nitrogen is separated from the compressed air in a nitrogen membrane separation unit. The separated nitrogen is stored in a nitrogen storage tank under pressure and released through a pressure control valve. The system is confined to a small footprint and is useful as a nitrogen source where conventional compressed nitrogen tanks are a safety or space issue. Systems to prepare nitrogen infused beverages are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to prior U.S. Application No.62/323,190, filed Apr. 15, 2016, the disclosure of which is incorporatedherein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a system to provide a continuous supplyof nitrogen gas located at point of utility which has a small footprintand low noise level such that it can be employed in retail, home orlaboratory settings.

BACKGROUND OF THE INVENTION

Nitrogen gas is employed in many utilities in the retail, home orlaboratory settings where traditional supply from storage cyclinders isinconvenient and may pose a safety or space consumption issue or simplyis an inconvenience. Nitrogen is employed as a small scale flush forpackaging, for flushing sample containers in a laboratory or as an agentfor beverage enhancement and dispence.

The inventors have discovered novel systems for preparation and dispenseof nitrogen infused beverages as described in PCT/US15/28876, filed May1, 2015, the disclosure of which is incorporated herein by reference inits entirety, in U.S. Provisional Application No. 61/993,700, filed May15, 2014, the disclosure of which is incorporated herein by reference inits entirety and in U.S. Provisional Application No. 62/299,608, filedFeb. 25, 2016, the disclosure of which is incorporated herein byreference in its entirety. The systems described in these applicationsdescribe a nitrogen supply from tanks of compressed nitrogen. However,for utilities such as retail dispense or home use, installing andremoving nitrogen cyclinders is at least inconvenient and requires spaceconsumption and is a source of safety concerns. Advancing technology hasmade available nitrogen generation systems wherein nitrogen is separatedfrom the air via compression/membrane technology. However, the inventorshave found that available systems having a sufficiently small footprintsuitable for incorporation into a beverage dispense unit to be placed inthe home or retail environment do not provide a continuous supply ofnitrogen at an elevated pressure sufficient to support, for example,nitrogen infusion systems as exemplified in the previously identifiedapplications. Moreover, systems having larger footprints which may becapable of supplying adequate nitrogen generate a high noise level whichis considered unacceptable for retail and home use systems.

Therefore, there is a need for a small footprint self-contained nitrogensupply system which supplies a continuous supply of nitrogen at apressure level sufficient to support a nitrogen infusion system whilebeing sufficiently quiet to be acceptable for use in a retail setting.

Thus an object on the present invention is to provide a stand-alonenitrogen supply system capable of supplying nitrogen gas continuously ata pressure and rate useful for packaging flush or other such utilities.

Another object is to provide a nitrogen supply system capable ofsupplying nitrogen gas continuously at a pressure sufficient to supportnitrogen infusion across a semi-porous or permeable membrane, which hasa sufficiently small footprint to allow incorporation into a beveragedispense unit and which is quiet in operation.

A further object is to provide a convenient, cost effective system whichdoes not require nitrogen supply from a compressed gas cylinder toinfuse a broad spectrum of beverages with nitrogen and dispense theinfused beverage in an attractive and facile method such that the systemmay be employed in a retail environment or in the home.

SUMMARY OF THE INVENTION

These and other objects are achieved by the present invention, the firstembodiment of which includes a system to supply nitrogen gas,comprising:

a compressed air feed;

a nitrogen membrane separator;

a nitrogen storage unit;

a pressure control unit; and

a release valve for nitrogen from the nitrogen storage unit.

A second embodiment includes a system for preparing and dispensing anitrogen infused beverage, comprising:

a bag-in-box beverage concentrate container;

a first diaphragm pump controlling flow of a beverage concentratethrough a beverage line from the bag-in-box container to a first flowcontrolling needle valve and from the first needle valve through a firstback check valve to a liquid mixing point,

a second diaphragm pump controlling water flow through a water line froma water supply to a liquid/gas contactor membrane unit and from thecontactor unit to a second flow controlling needle valve and from thesecond needle valve through a second back check valve to the liquidmixing point;

a liquid gas contactor membrane unit;

nitrogen supply system capable of supplying nitrogen gas continuously ata pressure sufficient to support nitrogen infusion across a semi-porousor permeable membrane of the liquid/gas contactor membrane unit, thenitrogen supply system comprising:

a source of compressed air;

a nitrogen membrane separator;

a nitrogen storage unit;

a pressure control unit; and

a release valve for release of nitrogen from the nitrogen storage unitto the liquid gas contactor unit;

a nitrogen infused beverage line from the liquid mixing point to abeverage faucet;

wherein

the beverage faucet is a slow release faucet such that the infusedbeverage in the nitrogen infused beverage line remains under pressureduring dispense of the beverage from the faucet, and

the nitrogen gas feed supply line to the liquid/gas contactor membraneunit comprises a check valve preventing liquid flow from the liquid/gascontactor membrane unit into the pressurized gas supply line.

In a further aspect of the invention a beverage dispense kit, comprisingat least the system described in the second embodiment in aself-contained unit is provided. The self-contained dispense kit may becapable of being affixed to a wall or a panel or may be a stand-alonefloor or countertop unit.

Any of the dispense systems or kits described herein may include achiller or refrigeration unit that cools at least the bag in boxbeverage concentrate container and may additionally cool the water, theliquid/gas contactor membrane unit and at least a portion of thedispense tower.

In a further special aspect, the beverage faucet for the nitrogeninfused beverage is a slow pour faucet optionally fitted with arestrictor nozzle or restrictor plate that allows for release of N₂ orN₂/CO₂ gas from the beverage when dispensed to a receiver.

In one embodiment, the present invention includes a method to supplynitrogen gas for utilities requiring a continuous nitrogen supply suchas for example, flushing packages before sealing or flushing equipmentfor drying or removal of air, comprising compressing ambient air to astorage receiver; optionally filtering the air before compression toremove particulates; optionally removing condensed moisture from thecondensed air; separating nitrogen from the compressed air in a nitrogenmembrane separation unit, collecting the separated nitrogen in anitrogen receiver; retaining the nitrogen in the receiver under apressure equal to or greater than the pressure required for the intendedend use of the nitrogen; and releasing the nitrogen through a pressurecontrol valve.

In another embodiment, the present invention includes a method forpreparing and dispensing a nitrogen infused liquid from the systemsdescribed in the above embodiments and further aspects thereof. Themethod comprises: transferring a beverage concentrate from thebag-in-box container through the first flow controlling needle valvethrough the first back check valve to the liquid mixing point underpressure from the first diaphragm pump,

simultaneously conveying water from the water supply through the liquidside of the liquid/gas contactor membrane unit under pressure from thesecond diaphragm pump and supplying the nitrogen gas at a pressure offrom 20 to 70 psi to a gas side of the liquid/gas contactor membraneunit;

generating nitrogen from ambient air by compressing the air andseparating nitrogen from the compressed air in a nitrogen membraneseparator;

storing the generated nitrogen in a nitrogen storage unit under apressure sufficient to operate a liquid gas contactor;

supplying the nitrogen from the nitrogen storage unit to the liquid/gascontactor;

infusing the nitrogen gas into the water across the membrane of theliquid/gas contactor;

further conveying the nitrogen infused water from the liquid/gascontactor through the second flow controlling needle valve through thesecond back check valve to the liquid mixing point;

mixing the beverage concentrate and nitrogen infused water at the liquidmixing point to obtain the nitrogen infused beverage;

supplying the nitrogen infused beverage under pressure to the beveragefaucet; and

dispensing the nitrogen infused beverage through the beverage faucet ata controlled rate to a receiver;

wherein the volume and pressure of the beverage concentrate and nitrogeninfused water combined at the liquid mixing point are controlled by thefirst and second flow controlling needle valves respectively, and

during the dispense of the nitrogen infused beverage, pressure isretained on the nitrogen infused beverage in the beverage line from themixing point to the faucet.

In a special embodiment of the invention the dispensed beverage isnitrogen infused chilled coffee.

The foregoing paragraphs have been provided by way of generalintroduction, and are not intended to limit the scope of the followingclaims. The described embodiments, together with further advantages,will be best understood by reference to the following detaileddescription taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the disclosure and many of the attendantadvantages thereof will be readily obtained as the same becomes betterunderstood by reference to the following detailed description whenconsidered in connection with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a nitrogen generator according to oneembodiment of the invention.

FIG. 2 is a three dimensional drawing of the nitrogen generatoraccording to one embodiment of the invention.

FIG. 3 is a three dimensional drawing of the nitrogen generatoraccording to one embodiment of the invention, showing vertical andhorizontal views of the system and indicating dimensions according toone embodiment of the invention.

FIG. 4 shows a bag-in-box beverage concentrate based dispense systemaccording to one embodiment of the invention.

FIG. 5 is a drawing of the basic components and arrangement of dispensetower according to an embodiment of the invention.

FIG. 6 is a drawing of a nitrogen gas liquid contactor unit according toan embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Throughout this description all ranges described include all values andsub-ranges therein, unless otherwise specified. Additionally, theindefinite article “a” or “an” carries the meaning of “one or more”throughout the description, unless otherwise specified.

According to the present invention the term “beverage” means anynoncarbonated aqueous liquid material that is a homogeneous liquidhaving a flavor due to dissolved components. According to embodiments ofthe invention the liquid supplied as a concentrate from a bag-in-boxcontainer may contain suspended solids. As used herein the termconcentrate describes any beverage in a high ingredient content formwhich is diluted with water to a level appropriate for consumption andenjoyment.

According to the present invention dispensing of the chilled beveragemeans opening a faucet of the system to allow the chilled N₂ infusedbeverage to flow from the system into a receiver such as a glass, mug orother drinking container. Throughout the following description the term“gas infused” will be employed to describe N₂ infused beverage.Dispensing of the gas infused chilled beverage is an element of thepresent invention wherein reduction of pressure on the gas infusedbeverage allows escape of infused gas and results in unique propertieswhich distinguishes the dispensed beverage by enhancement of thebeverage's flavor and/or appearance.

Throughout this description, the terms nitrogen, nitrogen gas, N₂ and N₂gas are used interchangeably and convey the same meaning unlessotherwise specified. Further, nitrogen infused water may be referred toas “nitro-water” and describes water infused with nitrogen or a mixedgas. Additionally, the prepared nitrogen infused beverage may bereferred to as “nitro-beverage.”

In a first embodiment, a nitrogen generation system is provided. FIG. 1shows a basic schematic diagram of the system containing an aircompressor (1), a compressed air storage tank (2), a nitrogen membraneseparator (3); a nitrogen storage unit (5); a pressure control unit (4);and a release valve for nitrogen (6) from the nitrogen storage unit.

This basic system may be modified with various controls, valves andcheck units as may be practised by one of skill in the art.

In an aspect of the first embodiment, as shown in FIG. 2, furtherstructural units are shown. Thus in FIG. 2 a air dryer (2) is inlinebetween the air compressor (1) and the compressed air storage tank. Thecompressed air tank is equipped with a moisture drain (9). A back checkvalve (5) is located between the N₂ separator membrane unit and the N₂storage tank (6). Pressure control (8) is shown on a control panel (notnumbered) and N₂ outlet valve is located in a mid-tank position.

As indicated in the views shown in FIG. 3 the nitrogen generator ofcertain embodiments may have a footprint of less than four square feetand a height of less than one foot. These dimensions may vary accordingto volume adjustment of the compressed air tank and nitrogen storageunit. However, it is clear that the nitrogen generator may have a footprint consistent with utility in a confined space such as a counter topor lab bench.

Optional components may include a particulate filter for the air to becompressed and further drain systems to remove condensate from thecompressed air. The pressure and temperature components of the systemmay be varied and such modification and control may be directed by oneof skill in membrane separation systems.

The inventors have surprisingly discovered that by collecting andstoring the N₂ gas obtained from the membrane separator in the storageunit under an elevated pressure, a constant and effective supply ofnitrogen to operate a nitrogen liquid contactor system may be obtained.The N₂ pressure in the storage unit may be from 10 to 100 psi,preferably from 15 to 80 psi and most preferably from 20 to 70 psi. Thevolume of the storage unit may be from 10 to 100 cubic inches and may bevaried to suit the requirements of the intended use of the nitrogen. Thestorage unit may be constructed of any material suitable for a pressurevessel as recognized by one of skill in the art. Stainless steel may bea material of choice when the generator is intended for use in a food orbeverage application.

The actual dimensions and configuration of the nitrogen generator may bevaried according to intended end use and supply requirement. A distinctadvantage may be obtained for example as shown by the dimensionsillustrated in FIG. 3. The foot print required of the generator is smallenough that it may be included as part of a kit as described in thefollowing embodiments or it may be a stand-alone unit for a bench ortable-top. Accordingly, the nitrogen generator of the present inventionmay be useful in a wide range of utilities where conventional compressednitrogen cyclinders are inconvenient or impractical. Additionally, thenitrogen generator offers added safety and reduced maintenancerequirement when employed in a retail environment.

In a second embodiment as shown schematically in FIG. 4, the presentinvention provides a system for preparing and dispensing a nitrogeninfused beverage, comprising: a bag-in-box beverage container (20); afirst diaphragm pump (12) controlling flow through a beverage line (3)from the bag-in-box container to a first flow controlling ejector (17)and from the first ejector through a first back check valve to a liquidmixing point (23), a second diaphragm pump (11) controlling water flowthrough a water line (2) from a water supply to a liquid/gas contactormembrane unit (8) and from the contactor unit to a second flowcontrolling ejector (16) and from the second ejector through a secondback check valve to the liquid mixing point (23); a controlledpressurized supply of a nitrogen from the nitrogen generator (22) to theliquid/gas contactor membrane unit; the liquid/gas contactor membraneunit (8); a nitrogen infused beverage line (18) from the liquid mixingpoint to a beverage faucet (FIG. 5); wherein the beverage faucet is aslow release faucet such that the infused beverage in the nitrogeninfused beverage line remains under pressure during dispense of thebeverage from the faucet, and the nitrogen gas feed supply line to theliquid/gas contactor membrane unit comprises a check valve (10)preventing liquid flow from the liquid/gas contactor membrane unit intothe pressurized gas supply line.

It is noted that for simplicity of the diagram the nitrogen generator 22is represented by a scaled down version of FIG. 1 and thereforecorresponds to the description of FIG. 1. However, the systems of FIG. 2or variations thereof may be shown as (22).

As indicated by the above description and in FIG. 4, the mixing of thebeverage concentrate and the nitrogen infused water takes place in lineunder pressure rather than at the dispense nozzle as would normally takeplace on a soda dispenser or bar gun. The carbonated water andconcentrate on a soda dispense system for example would bothindependently be fed to a nozzle and be mixed upon pouring the beverage.According to the design of the present invention nitrogenated water isblended with the concentrate under pressure which causes a forced inline nitrogenation of the concentrate as it is mixed with thenitro-water. This takes place as a result of the back pressure“restriction” in line from the slow pour faucet which has a restrictordisc causing the necessary line pressure to achieve the infusion.

In the embodiment shown in FIG. 4, the water supply may be provided froma pressurizable container (21) pressurized with nitrogen or nitrogenmixed gas through gas line (4) from nitrogen supply (22). In thisembodiment, the nitrogen is supplied through a manifold of independentgas regulators (25) to each of the diaphragm pumps (5), to theliquid/gas contactor membrane unit (6) and to the pressurizable watersupply container (4). Use of a water supply container such as shown in(21) offers an advantage that both the bag-in-box beverage concentrateand the water container may be cooled by a refrigeration or chillerunit. Alternatively, all or selected individual components of theembodiments shown in FIG. 4 may be cooled by one or more refrigerationor chiller units, preferably one common cooling unit.

The system may optionally incorporate an inline strainer and/orfiltration unit (not shown in FIG. 4) in the water line from the watersupply to the liquid/gas contactor membrane unit in order to protect thegas permeable membranes of the liquid/gas contactor membrane unit fromsolids which may be present in the water.

Bag-in-box containers are commercially available in a range of volumesizes and materials of construction. Any suitable container of volumesize convenient to the intended application may be employed. Generally,a container of 1 to 5 gallons is employed based on convenience ofhandling and size and structure of the refrigeration system to beemployed. However, systems constructed for high volume dispense may belarger, for example 10 gallons or more. The box component of thecontainer may be corrugated cardboard while the bag may be constructedof any material accepted for use in the food and beverage industry.

FIG. 4 schematically shows the arrangement of the fundamental componentsof the dispense systems of the present invention. However, in theconstruction of commercial functional units secondary components such assafety regulators, valves, couplings, harnesses, support structure andother functional components known to one of skill in the beveragedispense technology may be incorporated in the system. Such commercialarrangements are included in the present invention as long as thestructural components and arrangements disclosed herein are present.

The faucet (3) shown in FIG. 5 may be a slow pour faucet designed todispense the chilled gas infused beverage at a controlled rate to allowfoam formation upon dispense and provide the unique flavor andappearance associated with the product obtained via dispense from thesystem of this invention. Commercially available faucets typicallyemployed to tap beer are suitable for use as the faucet (3).

FIG. 5 shows a schematic diagram of a faucet tower assembly (1)according to an embodiment of the invention. In a highly preferredaspect of the invention a restrictor nozzle (2) is inserted in the tipof the faucet to further enhance the foam formation during liquiddispense. Restrictor nozzles providing differing dispensecharacteristics are known and commercially available. Additionally, arestrictor plate may be employed in place of or in combination with thenozzle to enhance the frothing effect of the dispense system. Theembodiment shown in FIG. 5 also includes a tap handle (4) which may be adecorative enhancement to the system, a drip tray (5) and quick connectcoupling (6) to line (18) shown in FIG. 4. The tap handle, drip tray andquick connect coupling are commercial enhancements to the system and arenot elements of the present invention.

In preferred embodiments the system is arranged or constituted in aself-contained unit or dispense kit that may be conveniently shipped toand placed in a commercial establishment for preparation anddispensation of specialty gas infused chilled beverages. It is unique inthat the nitrogen supply may be included as part of the kit and a standalone unit such as a nitrogen cylinder or tank is not necessary. Thesystem may or may not include a chilling or refrigeration unit capableof cooling the system components and beverage concentrate therein to atemperature less than ambient or room temperature. However, if thecooling capability is not included in the system provision to maintainthe beverage concentrate in a cooled state may be made according tomethods known to one of ordinary skill in the art.

The self-contained unit provides a user friendly and convenient chilledgas infused beverage preparation and dispensing unit especially suitedfor coffee bars, cafeterias, restaurants and other commercialestablishments where beverages are served. In a special embodiment thepresent invention provides a kit of the above described components thatincludes a mounting panel housing which attaches to a wall or panel andmounts some or all of the system components to the wall.

The chilling or refrigeration system is capable to cool the systemand/or the beverage concentrate therein to approximately 36° F. althoughthe choice of temperature will be dependent upon the beverage beinghandled in the system and the flavor and appearance sought. Chilling orrefrigeration systems suitable for the system of the present inventionare commercially available. One particularly preferred system is an IOWAROTO CAST “BREEZER” cylinder shaped refrigeration unit that mayconveniently contain the components of the system.

The nitrogen is supplied via a gas regulator valve through a pressurerated supply line to the liquid/gas contactor membrane unit. Thepressure of the water pumped into the liquid/gas contactor membrane unitand the pressure of the N₂ or N₂/CO₂ gas in the liquid/gas contactormembrane unit may be controlled independently of one another.

The diaphragm pump may be any appropriately sized diaphragm pumpconstructed for transfer of liquids for human consumption. Pumpssuitable for this use are commercially available and as one example, a“SHURFLO BEER ACE” diaphragm pump may be noted.

A check valve is located in the N₂ feed line to the liquid/gas contactormembrane unit to prevent liquid “backflow” from the liquid/gas contactormembrane unit to the nitrogen generator.

The liquid/gas contactor membrane unit is any suitable membrane unitcontaining hollow fibers such that N₂ or N₂/CO₂ mixture gas supplied tothe liquid/gas contactor membrane unit contacts the water via passagethrough a gas permeable membrane and is dissolved and/or dispersed intothe water to form a N₂ or N₂/CO₂ infused water feed.

In general description, a liquid/gas contactor membrane unit may beconstructed of a cylindrical tube containing hollow fiber membranes.Water is pumped into the space about the exterior of the hollowmembranes. N₂ or N₂/CO₂ gas at a set pressure as determined by thesupply regulator is passed into the interior of the hollow fibermembrane from where it permeates through the membrane and the permeateN₂ or N₂/CO₂ contacts the water on the exterior of the membrane andinfuses into the water. A schematic diagram of an example of aliquid/gas contactor membrane unit is shown in FIG. 6. As indicated inthe cross-sectional view B-B the contactor unit contains a series ofhollow fiber membranes (25) arranged within a solid casing (26) andsurrounded by fluid space (27). Liquid/gas contactor units areconventionally known and any unit which provides for gas-liquid contactacross a permeable membrane may be suitably employed. In one embodimentof FIG. 6, the N₂ is passed through the hollow membranes while the wateris passed through the fluid space surrounding the hollow fibermembranes. However, it is also possible to pass the water through thehollow fiber membranes while passing the N₂ through the fluid space.Variation and control of the gas pressure in the interior of the hollowfiber membrane relative to the pressure of the water on the exterior ofthe hollow fiber membrane allows for differing degrees of gas infusioninto the water.

The gas infused water (Nitro water) is transported from the liquid/gascontactor membrane through the flow controlling needle valve or brixvalve such as for example, a Brix Block® unit and then through a backcheck valve to the liquid mixing point where the nitrogen infused wateris mixed with the beverage concentrate.

Simultaneously, the beverage concentrate is pumped from the bag-in-boxcontainer by the diaphragm pimp directly to a separate beverageconcentrate flow controlling needle valve, preferably a Brix Block® unitand then through a back check valve to the liquid mixing point.

The structure of the liquid mixing point may be of any configurationwhich leads to complete mixing of the nitrogen infused water and thebeverage concentrate and may be as simple in design as a “Y” structurewhere the two lines fuse to one line or may be a more sophisticatedpassive liquid mixing unit as is well known in the art.

The flow rate and relative proportion of beverage concentrate andnitrogen infused water which enters the mixing point may be controlledby adjustment of the pressure from each of the diaphragm pumps and byadjustment of the flow through each of the flow controlling needlevalves.

The nitrogen infused beverage obtained at the liquid mixing point isretained under pressure and moves toward the dispense tower equippedwith a beverage faucet. In a preferred embodiment, the beverage faucetis a slow pour faucet that dispenses the chilled gas infused beverage ata rate of from 0.1 to 5 ounces per second, preferably from 0.5 to 3ounces per second and most preferably from 0.8 to 1.2 ounces per second.This effect and dispense rate may be further enhanced by insertion of arestrictor nozzle in the tip of the faucet as previously described.

Importantly, the nitrogen infused beverage in the beverage line betweenthe mixing point and the dispense faucet is maintained under a positivepressure even during dispense of the nitrogen infused beverage throughthe faucet.

In another embodiment, the present invention provides a method forpreparing and dispensing a chilled gas infused beverage from a system ofthe present invention. The method comprises transferring a beverageconcentrate from the bag-in-box container through the first flowcontrolling needle valve through the first back check valve to theliquid mixing point under pressure from the first diaphragm pump,

simultaneously conveying water from the water supply through the liquidside of the liquid/gas contactor membrane unit under pressure from thesecond diaphragm pump and supplying the nitrogen gas at a pressure offrom 20 to 70 psi to a gas side of the liquid/gas contactor membraneunit;

generating nitrogen from ambient air by compressing the air andseparating nitrogen from the compressed air in a nitrogen membraneseparator;

storing the generated nitrogen in a nitrogen storage unit under apressure sufficient to operate a liquid gas contactor;

supplying the nitrogen from the nitrogen storage unit to the liquid/gascontactor; infusing the nitrogen gas into the water across the membraneof the liquid/gas contactor;

further conveying the nitrogen infused water from the liquid/gascontactor through the second flow controlling needle valve through thesecond back check valve to the liquid mixing point;

mixing the beverage concentrate and nitrogen infused water at the liquidmixing point to obtain the nitrogen infused beverage;

supplying the nitrogen infused beverage under pressure to the beveragefaucet; and

dispensing the nitrogen infused beverage through the beverage faucet ata controlled rate to a receiver;

wherein the volume and pressure of the beverage concentrate and nitrogeninfused water combined at the liquid mixing point are controlled by thefirst and second flow controlling ejectors respectively, and

during the dispense of the nitrogen infused beverage, pressure isretained on the nitrogen infused beverage in the beverage line from themixing point to the faucet.

In one preferred embodiment the beverage concentrate is coffee that iscooled to a temperature of 30 to 40° F., preferably 32 to 38° F. andmost preferably, 34 to 37° F. Further, when the beverage is coffee theN₂ pressure in the liquid/gas contactor membrane unit is from 20 to 70psi and the N₂ content in the infused chilled coffee obtained when mixedwith the infused water at the liquid mixing point is from 20 to 80 ppm,preferably 30 to 60 ppm and most preferable 40 to 50 ppm.

The effect of the slow dispensing of the slow pour faucet is such thatupon release from the system and flow to the receiver such as a servingglass, N₂ gas escapes from the chilled coffee or other infused beverageas it cascades to the glass and results in the appearance of a head offoam or froth on the surface of the beverage providing a flavor, aromaand appearance unique to the product obtained according to the presentinvention.

Diaphragm pumps are conventionally employed in industry for the pumpingof beer, soda and other beverages, especially because such pumps arecompatible with carbonated as well as non-carbonated liquids. Althoughutility of a diaphragm pump has been disclosed in these embodiments, itmay be possible to employ other pumps suitable for liquids intended forhuman consumption.

The relative pressure of the N₂ gas in the liquid/gas contactor membraneunit and the pressure of the water from the diaphragm pump in theliquid/gas contactor membrane unit may be varied in order to impart moreunique appearance and possibly flavor enhancement to the dispensedchilled beverage obtained at the liquid mixing point. The ratio of theN₂ feed pressure to the liquid pressure of the water in the liquid/gascontactor membrane unit may be from 20/1 to 1/20.

One of ordinary skill may learn the effect of variation of the ratio ofthe N₂ gas feed pressure to the liquid pressure of the water in theliquid/gas contactor membrane unit on properties of the dispensedchilled beverage through experimentation and adjust the settings aslearned to obtain a N₂ infused chilled beverage having unique flavor,aroma and appearance. This study may also include the control of each ofthe flow controlling ejectors and relative mixing proportions.

In one embodiment the volume ratio of the beverage concentrate tonitrogen infused water mixed at the liquid mixing point may be from 1/10to 10/1, preferably 1/5 to 5/1, and most preferable, 2/1 to 1/2. Theseratios include all subranges and values within the described ranges.

In a further embodiment, the system may further contain a blast chillerunit, wherein a hot liquid such as brewed coffee concentrate or teaconcentrate is first rapidly chilled or superchilled to 40° F. or lowerand then charged to the bag-in-box container. Such rapid chill may serveto further enhance the flavor and aroma of the N₂ or N₂/CO₂ infusedchilled beverage when mixed with the nitrogen infused water anddispensed to a drinking glass or other receiver.

The above description is presented to enable a person skilled in the artto make and use the invention, and is provided in the context of aparticular application and its requirements. Various modifications tothe preferred embodiments will be readily apparent to those skilled inthe art, and the generic principles defined herein may be applied toother embodiments and applications without departing from the spirit andscope of the invention. Thus, this invention is not intended to belimited to the embodiments shown, but is to be accorded the widest scopeconsistent with the principles and features disclosed herein. In thisregard, certain embodiments within the invention may not show everybenefit of the invention, considered broadly.

The invention claimed is:
 1. A system for preparing and dispensing anitrogen infused beverage; comprising: a bag-in-box beverage concentratecontainer; a first diaphragm pump controlling flow of a beverageconcentrate through a beverage line from the bag-in-box container to afirst flow controlling needle valve and from the first needle valvethrough a first back check valve to a liquid mixing point, a seconddiaphragm pump controlling water flow through a water line from a watersupply to a liquid/gas contactor membrane unit and from the liquid/gascontactor membrane unit to a second flow controlling needle valve andfrom the second needle valve through a second back check valve to theliquid mixing point; a nitrogen generator in fluid communication withthe liquid/gas contactor membrane unit via a nitrogen gas teed supplyline; the liquid/gas contactor membrane unit; a nitrogen infusedbeverage line from the liquid mixing point to a beverage faucet; whereinthe nitrogen generator comprises: an air compressor as a compressed airfeed; a compressed air dryer; a compressed air storage tank having amoisture drain; a nitrogen membrane separator; a nitrogen storage unit;a pressure control unit; and a release valve for nitrogen from thenitrogen storage unit; the beverage faucet is a slow release faucet suchthat the infused beverage in the nitrogen infused beverage line remainsunder pressure during dispense of the beverage from the faucet, and thenitrogen gas feed supply line to the liquid/gas contactor membrane unitcomprises a check valve preventing liquid flow from the liquid/gascontactor membrane unit into the pressurized gas supply line.
 2. Thesystem of claim 1, wherein a volume of the nitrogen storage unit is from10 to 100 cubic inches.
 3. The system of claim 1, wherein a pressure ofgas of the nitrogen storage unit is from 10 to 100 psi.
 4. The system ofclaim 1, wherein the water supply comprises a pressurizable container tosupply the water.
 5. The system of claim 4, having a nitrogen gas supplymanifold comprising at least three nitrogen regulators, one regulatorcontrolling nitrogen supply and pressure to the first and seconddiaphragm pumps, one regulator controlling nitrogen supply and pressureto the liquid/gas contactor membrane unit, and one regulator controllingnitrogen supply and pressure to the pressurizable water supplycontainer.
 6. The system of claim 1, further comprising a chiller systemor a refrigeration system.
 7. The system of claim 6, wherein at leastthe bag-in-box beverage concentrate container is cooled by the chillersystem or the refrigeration system.
 8. The system of claim 6, whereinthe chiller or refrigeration system is capable of cooling at least thebag-in-box container to a temperature from ambient temperature to 34° F.9. The system of claim 1, wherein the beverage faucet is a slow pourfaucet optionally fitted with a restrictor nozzle or restrictor platethat allows for release of N₂ or N₂/CO₂ gas from the beverage whendispensed to a receiver.
 10. The system of claim 1, further comprisingan inline strainer and/or filtration unit in the water supply line priorto the liquid/gas contactor membrane unit.
 11. A beverage dispensingunit comprising the system for preparing and dispensing a nitrogeninfused beverage of claim 1 as one self-contained unit.
 12. A method forpreparing and dispensing a nitrogen infused beverage from the system ofclaim 1, the method comprising: transferring a beverage concentrate fromthe bag-in-box container through the first flow controlling needle valvethrough the first back check valve to the liquid mixing point underpressure from the first diaphragm pump, simultaneously conveying waterfrom the water supply through the liquid side of the liquid/gascontactor membrane unit under pressure from the second diaphragm pumpand supplying the nitrogen gas at a pressure of from 20 to 70 psi to agas side of the liquid/gas contactor membrane unit; generating nitrogenfrom ambient air by compressing the air and separating nitrogen from thecompressed air in the nitrogen membrane separator; storing the generatednitrogen in the nitrogen storage unit under a pressure sufficient tooperate the liquid gas contactor membrane unit; supplying the nitrogenfrom the nitrogen storage unit to the liquid/gas contactor membraneunit; infusing the nitrogen gas into the water across the membrane ofthe liquid/gas contactor membrane unit; further conveying the nitrogeninfused water from the liquid/gas contactor membrane unit through thesecond flow controlling needle valve through the second back check valveto the liquid mixing point; mixing the beverage concentrate and nitrogenfused water at the liquid mixing point to obtain the nitrogen infusedbeverage; supplying the nitrogen infused beverage under pressure to thebeverage faucet; and dispensing the nitrogen infused beverage throughthe beverage faucet at a controlled rate to a receiver; wherein thevolume and pressure of the beverage concentrate and nitrogen infusedwater combined at the liquid mixing point are controlled by the firstand second flow controlling needle valves respectively, and during thedispense of the nitrogen infused beverage, pressure is retained on thenitrogen infused beverage in the nitrogen infused beverage line from themixing point to the faucet.
 13. The method of claim 12, wherein thenitrogen infused beverage is dispensed through a faucet fitted with arestrictor nozzle or restrictor plate that allows for release of N₂ orN₂/CO₂ gas from the beverage when dispensed to a receiver.
 14. Themethod of claim 12, wherein the controlled rate of dispensing of thebeverage is from 0.1 to 5 ounces of nitrogen infused beverage persecond.
 15. The method of claim 14, wherein a content of N₂ in thedispensed N₂ infused beverage is from 20 to 50 ppm.
 16. The method ofclaim 12, wherein the nitrogen infused beverage is a nitrogen infusedcoffee.